package com.mystatusonline.webapp.taglib;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.jsp.tagext.TagData;
import javax.servlet.jsp.tagext.TagExtraInfo;
import javax.servlet.jsp.tagext.VariableInfo;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.appfuse.Constants;


/**
 * Implementation of <code>TagExtraInfo</code> for the <b>constants</b> tag,
 * identifying the scripting object(s) to be made visible.
 *
 * @author Matt Raible
 */
public class ConstantsTei
  extends TagExtraInfo {

  private final Log log = LogFactory.getLog(ConstantsTei.class);

  /**
   * Return information about the scripting variables to be created.
   *
   * @param data the input data
   * @return VariableInfo array of variable information
   */
  public VariableInfo[] getVariableInfo(TagData data) {
    // loop through and expose all attributes
    List<VariableInfo> vars = new ArrayList<VariableInfo>();

    try {
      String clazz = data.getAttributeString("className");

      if (clazz == null) {
        clazz = Constants.class.getName();
      }

      Class c = Class.forName(clazz);

      // if no var specified, get all
      if (data.getAttributeString("var") == null) {
        Field[] fields = c.getDeclaredFields();

        AccessibleObject.setAccessible(fields, true);

        for (Field field : fields) {
          String type = field.getType().getName();
          vars.add(new VariableInfo(field.getName(),
                                    ((field.getType().isArray()) ?
                                     type.substring(2, type.length() - 1) +
                                     "[]" : type),
                                    true, VariableInfo.AT_END));
        }
      } else {
        String var = data.getAttributeString("var");
        String type = c.getField(var).getType().getName();
        vars.add(new VariableInfo(c.getField(var).getName(),
                                  ((c.getField(var).getType().isArray()) ?
                                   type.substring(2, type.length() - 1) + "[]" :
                                   type),
                                  true, VariableInfo.AT_END));
      }
    } catch (Exception cnf) {
      log.error(cnf.getMessage());
      cnf.printStackTrace();
    }

    return vars.toArray(new VariableInfo[]{});
  }
}
